Self-collapsing container



sept. 17, 1968 .1.A. WIEDEMAN SELF-COLLAPS ING CONTAINER Filed oct. 18, 196e 2 Sheets-Sheet 1 M, pw. mm `WM WA.

Sept 17 1968 J. A. WIEDEMAN 3.401,837

SELF-COLLAPSING CONTAINER Filed 001;. i8, 1.966 2 Sheets-Sheet 2 F/G. 6 /2 /J/ /Jo /N VEN Ton JOHN A. W/EDEMAN United States Patent O 3,401,837 SELF-COLLAPSING CONTAINER John A. Wiedeman, 11520 SW. 43rd Terrace, Miami, Fla. 33165 Filed Oct. 18, 1966, Ser. No. 587,571 2 Claims. (Cl. 222-99) ABSTRACT F THE DISCLOSURE A self-collapsing thermoplastic container is constructed in such a manner that the Walls thereof exert an internal pressure upon the contents in such a manner that upon opening of the discharge outlet the content material may be disposed.

This invention relates to exible collapsible plastic containers. More particularly, the present invention relates to collapsible plastic containers of the type used to contain and dispense toothpaste, creams, medicaments and any similar viscous substances, such containers including means for facilitating the dispensing of the contents thereof.

In recent years, a considerable degree of enthusiasm has been generated in the chemical industry for a class of compositions termed, thermoplastic materials, polyethylene and polypropylene being prime examples of such compositions. The inherent advantages of these materials, namely, chemical inertness with respect to contents, ease of ornamentation and nominal cost, became self-evident to Workers skilled in the packaging arts and in the years following resulted in an industrial revolution in the packaging industry.

At an early stage in this revolution, the Ifeasibility of utilizing such materials for packaging toothpaste, cosmetics and the like was recognized. Unfortunately, a major prior art difficulty has been the eicient evacuation of the contents of the container. Thus, the normal evacuation or dispensing procedure involves the application by manual means of external pressure and in order to assure maximum evacuation the container must be continually squeezed in an inverted position or rolled end upon end (as in the case of thin walled tubes). Unfortunately, neither of these procedures has proven to be entirely satisfactory due to entrapment of contents or drawing in of air with subsequent lack of control in dispensing.

In accordance With the present invention, the prior art limitations described are eectively obviated by a novel container which automatically collapses as the contents thereof are dispensed. More specilically, the novel container is constructed in such manner that the walls thereof exert an internal pressure upon the content so that when the discharge outlet is opened the contents material may be dispensed with the concurrent collapse of the container. Application of the desired internal pressure is effected in accordance with the invention either by means of a U-shaped spring steel Iwire embedded in the side and closed end walls of the container or in an alternative embodiment by generating an innate force in the container Walls prior to filling so that the content material may be evenly advanced through the container and out of the discharge outlet upon removal of the cap, thereby resulting in the automatic collapse of the container.

It will be understood by those skilled in the art that the present invention is described for convenience largely in terms of tube contents wherein the container is a cylinder of oval cross-section closed at one end by a crimp and at the other end by a cap of the stopper type. However, it will be readily apparent to those skilled in the art that such is for purposes of exposition only and that any thermoplastic container may Ibe constructed as described herein.

ICC

The invention will be more readily understood from the following detailed description taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a side elevational view of a typical collapsible container constructed in accordance with the invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along 4line 3 3 of FIG. l;

FIG. 4 is a sectional view of FIG. 1;

FIG. 5 is a perspective view of a coil spring wire employed in the practice of the invention prior to insertion in a container;

FIG. 6 is a side elevational view of an alternative container constructed in accordance with the invention;

FIG. 7 is a side elevational View of the container of FIG. 6 after a portion of the contents thereof have been dispensed; and

FIG. 8 is a side elevational view of the container of FIG. 7 after the container has been completely evacuated or before being filled.

With reference now more particularly to the drawing wherein like numerals denote corresponding parts, a collapsible container of the type normally utilized to contain toothpaste and the like is shown. The inventive container 10 is essentially a cylinder of oval across-section constructed of a thermoplastic material having one end sealed as at 11, thereby defining a chamber 20, and the other or discharge end provided with a neck portion 12 through which a discharge passage extends. In order to removably secure a stopper 14 in neck 12 to prevent the inadvertent escape of contents therethrough passageway 13 is enlarged as at 15 and provided with tapering side walls 16 and 17. Stopper 14 is of the same configuration and size as walls 15 and 16, so assuring that passageway 13 will receive the stopper 14 and hold it securely until removed by pulling upon tab 18 secured thereto, tab 18 being fastened to neck 12 `by means of an elongated ribbon 19.

Embedded in the thin side and end walls of container 10 is a U-shaped spring steel wire, designated W, comprising a pair of leg members 21 connected to each other at the lower extremity of container 10 by means of base member 22. Leg members 21 of spring Iwire W are normally in a coiled position (note FIG. 5); however, in the fabrication of tube 10 members 21 are held in an open position, and after filling container 10, extend in a straight `line along the wall of the container (see FIG. l).

In use, tab 18 is pulled away from neck 12, so resulting in the removal of stopper 14 and opening of passage 13. Upon the application of external pressure to the side walls of container 10, contents of the tube are ejected. As chamber 20 is gradually evacuated, leg portions 21 of wire W cause end portion 11 to Wind upon itself (see FIG. 4) until container 10 is virtually empty. At this point wire W will once again assume its normal position as shown in FIG. 5.YY

The inventive container described herein has been found to -be particularly advantageous in that essentially all of the contents of container 10 will be evacuated without the necessity of the user collapsing the tube and rolling it end upon end to assure maximum evacuation of contents, thereby avoiding the prior art limitation of entrapment of contents.

Referring now to FIGS. 6, 7, and 8, an alternative embodiment of the present invention is shown wherein container 30 is so constructed as to automatically collapse so that when the discharge outlet is opened the content material may be evenly advanced through the container and out of the discharge outlet.

This embodiment of the invention involves pretreating the thermoplastic composition employed in the fabrication of the container by impressing an innate force or prestress upon walls 31 and 32 of container 30, thereby compelling end 33 to coil upon itself as the tube contents are evacuated. This unique effect is attained by subjecting container 30 to a heating step while in the coiled position as shown in FIG. 8. Thus, this goal is attained by heating container 30, in the coiled position as shown in FIG. 8 to a temperature of the order of 200 C. for a time period of the order of 5 minutes maxima being dictated by the softening point of the material. Thereafter, tube 30 is lled with the desired content material, thereby resulting in unwinding of the container and the development of an internal force. Upon opening of the container, the content material is dispened and the walls automatically collapse, so resulting in coiling of the tube as shown in FIGS. 7 and 8.

While the invention has been described in detail in the foregoing specification and the drawing similarly illustrates the same, the aforesaid is by way of illustration only and is not restrictive in character. The several modiiications which will readily suggest themselves to persons skilled in the art are all considered within the scope of the invention. Thus, it will be understood that the configuration of the container utilized may take the form of a rectangle, a chamber or any other polygonal form.

What is claimed is:

1. A collapsible thermoplastic container for uent material including a chamber defined by a pair of opposite side walls, an end wall and a neck portion mounted opposite the said end wall, said neck portion having a conduit communicating with said chamber, stopper means removably mounted on said neck portion, and means for collapsing said container, to exert internal pressure on Said fluent material, said means comprising a pair of elongated, 'but normally coiled, spring members embedded in said opposite side walls.

2. The container of claim 1 wherein said spring mem bers are joined to each other and to said end wall by an elongated member in said end wall connecting said spring members.

References Cited UNITED STATES PATENTS 1,731,703 10/1929 Bourke 22299 2,430,046 11/ 1947 Dreyfus 222-107 ROBERT B. REEVES, Primary Examiner.

HADD S. LANE, Assistant Examiner'. 

